Background
Calcification of various cardiovascular structures is associated with aging, chronic kidney disease, and following radiation therapy.
Mitral annular calcification (MAC) is a chronic degenerative process of the mitral valve ring; it was first described in 1908 by Bonninger as associated with complete heart block.
Dewitzky presented detailed pathologic descriptions of 36 cases and demonstrated the close resemblance to a similar process that had been described in the aortic valve in 1904 by Monckeberg.
Yater and Cornell in 1935 histopathologically demonstrated extension of a calcific mass into the Bundle of His leading to heart block.
Calcification of the annulus fibrosus of the mitral valve was commonly found in older people at autopsy and was considered to be a sequela of rheumatic heart disease.
However, evidence of previous disease was often absent; the lesion is now generally regarded as the end stage of an inflammatory process.
MAC and atherosclerosis share similar risk factors, and the presence of MAC may reflect the intensity and duration of exposure to these risk factors.
Interestingly, MAC has been proposed as a visible barometer of the burden of atherosclerotic disease.
Mitral annular calcification is a growing problem in the elderly. It causes mitral stenosis and regurgitation, which are hard to treat.
Furthermore, studies have suggested that the presence of MAC is independently associated with a higher incidence of cardiovascular disease (CVD) and cardiovascular death and stroke.